Preheat oven to 375°. Coat 2 baking sheets with cooking spray.
In a medium skillet, melt butter over medium-high heat. Add onions and peppers and sauté 5 minutes. Add salt, cumin and crushed red pepper, stir to combine. Add chicken strips and cook 5 minutes more, until chicken is heated through and vegetables are tender.
Meanwhile, roll out each biscuit with a rolling pin to flatten to a ¼-inch thickness. Place 4 biscuits on each baking sheet and bake for 8-10 minutes. Remove from oven and flip each crust.
Layer each crust with 2 tablespoons salsa, then top evenly with chicken mixture. Top each pizza with a slice of pepper jack cheese. Return to oven for 8-10 minutes, until cheese is melted and golden brown.
Top each pizza with cilantro. Serve with guacamole and sour cream.